ClassNotFoundException

I am doing a simple entity bean example program using JBOSS. I am getting class not found exception though I have put the driver mysql-connector-java-3.1.8a.zip file into the C:\jboss-3.2.3\server\default\lib directory and mysql-ds.xml in the C:\jboss-3.2.3\server\default\deploy. I am not using standardjbosscmp-jdbc.xml file, is this mandatory file.